There are applications for antennas which function in an elongated configuration, but which must initially be packaged in a retracted configuration of smaller envelope size. A classical application is for spacecraft antennas, where the volume for stowage in flight to orbit is very limited, but which requires a deployed configuration of larger envelope size and length during orbital service. During its service it is deployed positioned outside of the spacecraft, and the stowage envelope limitations no longer apply.
For spacecraft applications, and for most other applications where the antenna of this invention is important, lightness of weight, rigidity in its deployed condition, insensitivity to temperature, and non-conductivity of supporting structure are important requirements.
Reliability of extension to the deployed configuration is another prime requirement. Because of weight limitations, the structural elements must be lightweight. The means to deploy the antenna must be simple in construction, and involve the fewest possible moving or manipulated parts.
It is an object of this invention to provide a lightweight helical antenna which can be compressed to a flattened configuration and reliably be driven to a rigid deployed configuration by simple and reliable force means.